Two of a target of thirty-eight participants with chronic central serous chorioretinopathy will be enrolled initially. In this Phase II, single-center, placebo-controlled, double-masked, randomized trial, investigational product will be administered to two different groups. Half of the participants will be randomized to 5 mg oral finasteride for the initial three months. The other half of the participants will be randomized to placebo for the first three months. At the end of three months of treatment, all participants may be followed for at least four years and nine months. During this follow-up period, all participants will be able to receive finasteride therapy PRN if subretinal fluid re-emerges. The PRN phase will last until the last participant completes the five years of follow-up. Other standard care treatments, such as photodynamic therapy, will also be permitted after the primary outcome at three months.